For various reasons, including diet, substance use, illness, injury or surgery, patients may require supplementation of their natural body functions in order to remove fluid-containing dissolvable waste products from their blood or gastrointestinal (GI) fluids. Several procedures known for this purpose are dialysis, hemodialysis, hemofiltration and hemodiafiltration. For example, dialysis is used to remove soluble waste and solvent from blood; hemofiltration is used to remove plasma water from blood; and hemodiafiltration is used to remove both unwanted solute (soluble waste) and plasma water from blood.
It is also known that a number of metabolic toxins such as mercaptans, free fatty acids, and conjugated bilirubin and endotoxins are completely bound with proteins in the bloodstream. Because of the size of the molecules and the strong body interaction of the protein toxin complex, it is difficult or impossible to select and remove from blood toxins bound to albumin by traditional blood purification methods such as hemodialysis. Hemoperfusion is a blood purification method that works in conjunction with activated carbon or iron exchange resins that absorb materials including the protein-bound toxins.
It is well known that individuals that are diagnosed with chronic renal insufficiency can be treated with the aid of dialysis. Substances that are usually eliminated in the urine are removed with the assistance of a filtering device that contains a semipermeable membrane. However, during the course of the long term, hemodialysis complications can occur that include chronic accumulation of inorganic phosphate in dialysis patients. Phosphate body agents can be administered orally and used as therapeutic agents, which are intended to prevent the reabsorption of food phosphates in the gastrointestinal tract.
Another treatment procedure that has been used is peritoneal dialysis, wherein a sterile saline solution is injected into the peritoneal cavity and remains there for a period of time. During this period, some toxic substances may cross the peritoneum that serves as a natural membrane, and are thereafter removed from the body along with the solution. This procedure is semi-invasive and carries a risk of infection. Also, such a procedure is not suitable for the removal of a variety of substances, and may not be suitable for all patients.
A disadvantage of various of the above-mentioned treatments is that the biological fluids of the patient have to be transferred from the body, circulated through an exterior treating device, and then returning the biological fluids back to the patient. These treatments are typically done in a medical setting such as a hospital, and require the patient to travel to and from the hospital where the procedure is performed. This process can be time-consuming and disruptive to the normal activity of the daily life of the patient.
Devices are also known, which deliver a drug agent to an environment of use, are known. These devices are made with a wall formed of a material that is permeable to an external fluid and substantially impermeable to the beneficial agent. The wall is known to surround a compartment that contains the agent and a passageway through the wall for dispensing the agent.
A known group of polymers called non-absorbed polymers are designed to operate in the gastrointestinal tract and selectively bind specific target molecules. These polymers are orally administered in capsule or tablet form, pass through the stomach and into the intestines where targeted molecules bind with the polymer, pass through the intestinal tract, and are excreted from the body.
The disadvantage of the orally administered treatments resides in the fact that they are typically designed to treat an individual ailment. A separate treatment must be ingested in order to effectively treat each diagnosed ailment. Furthermore, since these treatments are dispersed within the GI tract and not absorbed by the body, there is a chance that some of the agents can remain in the body for extended periods of time.
The need exists for an in-vivo bioreactor having the capability of removing undesirable intestinal, blood substances, or metabolites, which avoids the deficiencies of the prior devices and methods.